US2301774A - Driving gear for bicycles - Google Patents

Description

Nov. 2- c. J. ENGLERT DRIVING GEAR FOR BICYCLES Filed Nov. 14', 1940 3 Sheets-Sheet 1 g v Inventoi' Attorney M Nov. 10, 1942.

Filed Nov. 14, 1940 C. J. ENGLERT DRIVING GEARAFOR BICYCLES a Shejets-Sheet 2 1 1 iiilinif ii in'iil @IIIIRIIHI m fii'illlllllllll!@IIIIIIIII IIIIIIIIEMHI Fig- 7 Fig 5 Inventor g I [0H0 Nov. 10, 1942. c. J. ENGLERT DRIVING GEAR FOR BICYCLES Filed Nov. 14, 1940 3 Sheets-Sheet 3 Inventor LU flitorney Patented Nov. 10, 1942 UNITED STATES PATENT OFFICE DRIVING GEAR FOR BICYCLES Conrad J. Englert, Schenectady, N. Y.

Application November 14, 1940, Serial No. 365,690

9 Claims.

This invention relates to the driving gear for bicycles and the general object of the invention is to provide such a gear constructed to give the bicycle rider a mechanical advantage on the working stroke of the pedals.

In the ordinary bicycle the pedals and pedal arms rotate about the axis of the driving sprocket and the rate of motion of the pedals and sprocket are the same throughout a revolution of the latter. The up or return stroke of the pedal requires the same time as the down or working stroke and the pedal remains at the same radial distance from the sprocket axis at all times. When the pedal arms are horizontal the leverage is most favorable, but the length of the lever arm is limited by the distance between the ground and the sprocket axis.

It is an important object of my invention to mount the pedals and their arms so they turn about an axis located forwardly of the sprocket axis and provide driving connections between the pedal arms and sprocket. By this arrangement the vertical stroke of the pedal remains as usual but the pedal arm when horizontal places the pedal at a distance from the sprocket axis greater than the length of the pedal arm. A mechanical advantage is thereby gained on the working stroke but the high and low positions of the pedals are the same as in the ordinary bicycle.

In the usual bicycle the sprocket and pedal arms are fastened together and one revolution of the pedals produces one revolution only of the sprocket. In my present invention I introduce a gear and pinion connection between the sprocket and pedal arms so proportioned as to cause the sprocket to turn faster than the pedals, thereby taking advantage of the increased power growing out of the eccentric mounting of the pedal arms. Where desired, however, the gearing can be in such ratio as to cause one revolution of the sprocket for each turn of the pedals.

With these and other objects in view which will appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set forth in the claims.

In the accompanying drawings, where two forms of my invention are shown,

Fig. 1 is a side elevation of the preferred form of my invention, one pedal being in high position at the beginning of a down working stroke,

Fig. 2 is a back elevation of the structure shown in Fig. 1, both pedals being illustrated,

Fig. 3 is a vertical section, on an enlarged scale, on line 33, Fig. 1,

Fig. 4 is a detail vertical section on line 4-4, Fig. 1, enlarged, V

Fig. 5 is a side elevation of the gear and pinion case seen in Fig. 1,

Fig. 6 is a vertical section on line 6-6 of Fig. 5,

Fig. 7 is a detail vertical section on line 1-1, Fig. 1, enlarged,

Fig. 8 is a view similar to part of Fig. 6 showing a modified form of the invention,

Fig. 9 is a cross section through the rear wheel of a bicycle showing the relation between the spokes and their supporting plates, and

Fig. 10 is a plan view showing the rear wheel of Fig. 9 on a reduced scale and the manner in which it is connected to the driving mechanism by the chain.

In illustrating my invention I have not thought it necessary to show the whole frame and wheels of the usual bicycle, but have shown three frame bars III, which support the matter to be described hereinafter. These bars are of usual location on the bicycle, and being supported by the wheels, not shown, afford a mounting for my invention. The bars are directly connected to a casing II, as suggested in Fig. 5, having a cylindrical form with its axis occupying the same place as the sprocket axis of the usual bicycle. The casing comprises a circular shell I2, having right and left end plates l3 and M, respectively, as viewed in Fig. 6, secured to the casing as at,|5 to form a closed chamber [6.

Extending concentrically through the chamber is a driving shaft designated at H, the ends of which are substantially alike. Each end is tapered as at 18, see right side of Fig. 6, and

fastened thereto is a hub I9, which is tapered internally to fit the end of shaft I! and is held in place by a screw 20, threaded into the end of the shaft, and engaging a hub-shoulder 2|. The outer cylindrical surface of the hub carries the inner ring of a ball race 22, the outer race 23 of which is received by a bearing seat 24, which is formed integral with plate [3. In a similar way the left end of the shaft carries a hub 25, the outer ball race at that end being housed in a race seat 26, integral with plate It. The shaft I! is thus mounted to rotate freely and concentrically on balls 21 with respect to the supporting casing.

Secured to the shaft [1 between the two hubs on the shaft is a gear 28, held against a collar 29 on the shaft by a nut 30. The gear 28 turns with the shaft and meshes in with a pinion 3|, which is'fast on a stud-shaft 32, the left end of which is driven into an inner ball race 33, the corresponding outer race 34 of which is housed in a seat 35, formed on plate i i, and balls 36 complete the bearing.

At the right of pinion (ii is a second ball bearing, having inner and outer races 31 and 38, respectively, which gives additional bearing for the stud-shaft 32. Race 38 is located in a race seat 39, formed on the right plate I3. A dust plate it is set into the lower part of the plate l 4, to protect the left end of the stud shaft and its bearings. There is a bottom cover 4! to the casing H, which is held in place by screws 12. This arrangement holds the ball races 3 and 33, and the dust plate 49, firmly in place.

The right end of the stud-shaft has secured thereto a second pinion 43, which meshes in with a ring gear at, which in turn is fastened at several points as at 5 to the driving sprocket 45. A fiange i? on the sprocket fits closely to the inner surface of the ring gear it and receives an outer ball race 8 for balls 19, the inner corresponding race 56 is driven onto a shouldered race seat integral with plate 53. There is sufficient clearance between the sprocket and pinion i3 and a dust guard at 52 to permit free rotation without frictional engagement with these parts. The sprocket will be connected by the usual chain, not shown, to the rear wheel of the bicycle. M is shown in Fig. 6.

From the matter thus far described, it will be seen that rotation of shaft 51 will turn drive gear 28, also pinions 3i and 43, and the ring gear 44 which drives the sprocket wheel. shows the preferred form of the invention, wherein pinions 3! and 53 are of equal diameters, hence one rotation of gear 28 will cause one rotation of the sprocket.

The mechanism for driving the shaft H is shown more particularly in Figs. 1 and 2. As in the usual bicycle, I provide two pedals, one on each side of the fixed casing, and set them 180 apart on their axis.

Unlike the usual construction, however, the pedals do not rotate about the axis of the sprocket wheel, but are mounted so that their axis is in front of the shaft H, the pedals and parts associated with them are the same on both sides of the casing H, and include an inner ring 5 3, which is secured to the adjacent casing sideplate, so that it is fixed with respect to the vehicle frame.

This inner ring E i is fitted to a seat 55, which is provided on the adjacent casing side plate l3 and secured thereto at tapped out holes 56, with screws 5?, as shown in Figs. 1 and 5. Rotatable around each ring 54 is a second ring 58, which rolls on balls til. The inner race for balls 59 is formed in part by ring 54, as at (it, and in part by a separate ring ti, which is secured to the inner ring by screws t2, as shown in Fig. 4-. The rings have concentric concave surfaces to receive the balls 5d, the outer ring 58 moves with a, minimum of friction.

Secured to each outer ring 58 is an arm 63, the outer end of which is shown in detail in Fig. 3. This arm 83 has a cupped bearing seat 64 receiving an outer ball race 65, while the inner race is formed of two race-forming elements 56, which are driven on the reduced end Bl of a pedal stud-shaft 68, after the balls 69 are in place. A nut 70 is threaded on the inner end 3-! cf thestud-shaft 68, which holds the elements At 53 an exposed tooth of ring gear Fig. 6

pedal, shown conventionally at 13.

66 against the stud-shoulder H of the larger part of the stud shaft 68.

An internal nut 12 is threaded into the cupped bearing seat 54, which holds the outer 65 in place. The stud 68 is extended throughout the foot The pedal and stud shaft 68, therefore, rotate around the fixed ring 55 When the rider operates the pedals in the usual manner.

In Fig. 1, the vertical lines A-A and 13-3 pass through the axis of the shaft I? and ring 54, respectively.

Stud 68, therefore, rotates in a path eccentric with respect to the shaft i1, and when it is in front of the shaft it is farthest from it, and is nearest to the shaft when it is behind it. In order to communicate motion from the pedal to the shaft, some account must be taken of the eccentric path of the pedal. As shown herein, I provide a sliding driving connection between the stud 88 and shaft ll.

Returning to Fig-6, each hub i9 and 25 is formed integral with an inner block 14. Each of these blocks is associated with a second similar block 1'5, spaced outwardly from its companion.

Between these blocks lie rolls 75, with peripheries V-shaped as at 11. Fig. 7 shows the mounting for a roll. A bearing 78 extends through the block Hi and has a head 78 set into the block. A screw 80 extends through the other block 15 and is threaded into the bearing 13. The screw 88 has a head 8:, which is set into the block 15, and the heads 19 and 8! hold the two blocks together. Rctataole around each bearing 18 is one of the rolls l6 and ball bearings 82 at each of their sides, to permit free turning of the rolls on their centers. It being the duty of these side-ball-bearings 82 to prevent friction due to side strains subjected to these parts.

Each pair of blocks forms in effect a crank arm on the shaft I7. As seen in Fig. 1, the greater part of the length of the crank arm lies at one side of the shaft ii, and from Fig. 2 it is seen that the crank arms, one at each side of easing H, project in opposite directions. Each crank arm is caused to turn by a connector 83, having a head 84 into which the large part of the corresponding stud 68 is threaded.

The connector 83 extends from its head towards the blocks on the same side of the casing H and is slotted as at 85, the parallel sides 35, which form the slot having ribs V-shaped in crosssection, to fit the peripheries ll of the rolls it. The slot 85 is of such length as to permit a complete rotation of the stud 68, without interference between the blocks and the connector.

In operation, the rider of the bicycle will turn the pedals in the usual manner, in the direction of arrow a, as shown at the top of Fig. 1, around the center of ring 54 as an axis. Starting from the position shown in Fig. 1, the pedal will move to the right, along a path which moves away from the shaft ll, causing the slotted part of the connector 83 to move in a direction to increase the length of the power arm of the connector, which acts on its blocks or crank arm. The rider is therefore at an advantagefwhich increases until the pedal reaches the horizontal line C, at a position in front ofthe shaft 11. As the pedal continues to turn, it starts to move back toward the shaft, the advantage diminishing until the pedal crosses line 3-3, after which the down motion of the pedal ceases. At this time, the other pedal is in high position, and it is pushed down in turn to repeat the motion and eifect on shaft I! of the pedal already described.

Throughout the downward working stroke of each pedal, except at the instant of starting and finishing, the power arm represented by the effective length of the connector in descent is longer than could be obtained with the usual bicycle drive, without excessive permanent lengthening of the pedal arms. The turning of the blocks causes turning of the shaft I1 and the sprocket to drive the vehicle, as already described.

If fuller advantage is to be taken of the relationship already described, the gearing shown diagrammatically in Fig. 8 may be used.

This figure is similar to Fig. 6, but instead of having the two pinions and gears of equal diameters, that shown in Fig. 8, which shows the pinion 90 to be smaller in diameter than pinion 3|, shown in Fig. 6, and the driving gear BI is shown to be necessarily larger in diameter than the drive gear 28, shown in Fig. .6, hence the stub-shaft 32 now turns faster than in the preferred form, shown in Fig. 6. The actual amount of the different speed ratios may be determined by the ratio of the diameters of the driven pinions, and the ratio of the diameters of the driving gears.

Because of the relation between the pedal, the eccentric ring, and the sprocket wheel, shown particularly in Fig. 2, the chain is spaced farther from the riders pedal than usual, being nearer the center-line of the bicycle frame than ordinarily. As a result of this relationship, the sprocket pinion I is nearer the central plane of the driven rear wheel than customarily, and therefore, provision must be made for accommodating this condition to the spokes of the rear wheel of the bicycle, as shown in Fig. 9, the hub -IOI of the rear wheel, designated generally at I02, has a relatively small ring or flange I03 secured at one end thereof, while the sprocketpinion I00 is secured to the other end thereof. A relatively large ring or flange I04 is secured to the hub IIII, between the sprocket pinion I00 and flange I03, as suggested in Fig. 9. The long spokes I05 connect to the small flange I03, and the rim I06 of the wheel I02, forming with the central plane of the wheel, some such angle as that designated at a, in Fig. 9. In that figure, the dot and dash line represents the central plane of the weave. In order that this same angle may be formed by the spokes I08, I use the large flange I04, connecting the short spokes I08 to the periphery of the large flange, thus preserving the same angle between the central plane of the wheel and the short spokes I08, as that indicated at a.

The reason for the large flange I04 will be apparent from Fig. 10, where the dot and dash line IIO represents the central plane of the rear wheel and of the driving mechanism. The chain H2 is driven by the sprocket 46 and drives the sprocket-pinion I00.

By the disposition of the short spokes I08 and the large flange I04, as suggested in Fig. 10, I am enabled to place the driving pedals symmetrically with respect to the center of the bicycle, which in Fig. 10 is indicated by line H0.

From the foregoing, it will be seen that I have provided a driving gear for bicycles, wherein the pedals move around an axis in front of the sprocket axis. It will be seen also that power is transmitted to the shaft I"! through a sliding connection which provides the advantage of the eccentric relationship to be communicated to the shaft I'I. Further, the gearing within the casing transfers the rotation of the shaft to the sprocket either by a 1 to 1 relation, as that shown in Fig. 6, or by means of the driving gear SI, and pinions and 43 as that shown in Fig. 8, which is with a mechanical advantage.

It will further be understood that I have modified the rear wheel of the bicycle to permit a symmetrical arrangement of the driving pedals, and to preserve the same angle between the right and left spokes of the rear wheel I02 with respect to the central plane of the bicycle, as suggested in Fig. 10, by using a relatively large flange or ring I04 to which the short spokes I08 are attached. With such an arrangement, the plane of the driving chain can be kept parallel with the central plane of the bicycle, and sufficient room provided for the rear sprocket and the driving chain.

Having thus described my invention, it will be seen that changes and modifications may be made therein, by those skilled in the art without departing from the spirit and scope of the invention, and I do not wish to be limited to the details herein disclosed.

But what I claim is:

1. In driving gear for a bicycle having a frame, a hollow casing fixed with respect to the frame, a shaft extending therethrough and supported by each side of the casing, means to rotate the shaft, a relatively large gear secured to the shaft and located within the casing, a pinion meshing with the ear, a stub shaft to which the pinion is secured rotatable about an axis fixed with respect to the casing, a second pinion outside the casing secured to the stub shaft, 2. ring gear outside the casing meshing with the second pinion outside the casing, and a driving chain sprocket wheel secured to the ring gear.

2. In driving gear for a bicycle having a frame, a casing supported by the frame, a driving haft extending through the casing and supported by each side of the casing and rotatable with respect thereto, a gear secured to the shaft within the casing, a stub shaft rotatable on the casing, a pinion secured to the stub shaft and meshing with said gear, a second pinion outside the casing secured to the stub shaft rotating with the first pinion, a ring gear meshing with a second pinion outside said casing, means to mount the ring gear for rotation with respect to and outside the casing, and a driving chain sprocket wheel secured to the ring gear.

3. In a driving gear for a bicycle having a frame, a hollow casing supported by the frame, a shaft extending through and supported by each side of the casing and rotatable with respect to the casing, a pair of driving arms secured to the shaft, one located on each side of the casing, a gear within the casing secured to the shaft, a stub shaft extending through and rotatable with respect to the casing, a pinion within the casing secured to the stub shaft and meshing with the gear, a second pinion secured to the stub shaft outside the casing, a ring gear outside the casing meshing with the second pinion, means to mount the ring gear for rotation with respect to the casing, and a driving chain sprocket wheel secured to the ring gear, the ring gear and sprocket wheel being located between the casing and one of said driving arms.

4. In a driving gear for a bicycle having a frame, a hollow casing supported by the frame, a shaft extending through and supported by each side of the casing and rotatable with respect to the casing, a pair of driving arms secured to the-shaft, one located on each side of the casing, a drive gear within the casing secured to the shaft, a stub shaft rotatable with respect to the casing, a pinion secured within the casing to the stub shaft and meshing in with the gear, a second pinion secured to the stub shaft, a ring gear meshing in with the second pinion outside the casing, means to mount the ring gear outside the casing for rotation with respect to the casing, and a driving chain sprocket wheel secured to the ring gear, the ring gear being located between the'said casing and one of the said driving arms.

5. In a bicycle driving gear, a frame for the bicycle, a hollow casing supported by the frame, a shaft extending through the casing and rotatably mounted on each side of said casing, a pair of pedal arms mounted to rotate eccentrical- 1y with the shaft, means to cause the shaft to rotate with a constant speed as the pedal arms rotate variably, a gear within the casing secured to the shaft, a pinion meshing in with the gear and rotatable with respect to the casing, a second pinion outside the casing rotating with the first pinion and having a diameter different from the first named pinion, a second gear outside the casing meshing in with the second pinion, and a driving chain sprocket wheel secured to the second gear.

6. In a driving gear for a bicycle having a frame, a casing secured to the frame, a shaft extending through and supported by and rotatable with respect to each side of the casing, a pair of pedal arms rotatable about a given axis, means to cause the said shaft to rotate with a constant speed when the pedal arms rotate variably, the said pedal arms rotating about a center in front of the axis of the shaft with respect to the bicycle frame, a gear of given diameter within the casing secured to the shaft, a pinion of smaller diameter than the second pinion, meshing in with the gear, and rotatable with respect to the casing, a second pinion outside the casing rotating with the first pinion, a second gear smaller in diameter than the first gear outside the casing, meshing in with the second pinion of a larger diameter than the first pinion, and a driving chain sprocket wheel secured to the second gear.

7. In a driving gear for a bicycle having a frame, a hollow casing having spaced sides fixed with respect to the frame, a shaft extending through the casing and supported by each of said sides, means to rotate the shaft, a relatively large gear secured to the shaft within the casing and located between said sides, a pinion in the casing meshing with the gear, a stub shaft rotatably mounted with respect to the casing and to which the pinion is secured, a second pinion secured to the stub shaft, a ring gear rotatably mounted on the exterior of one of said sides of the casing and meshing with the second pinion, and a driving chain sprocket wheel secured to the ring gear.

8. In a driving gear for a bicycle having a frame, a hollow casing having spaced vertical walls mounted on the frame, a shaft extending through the casing and supported by each of the walls, means to rotate the shaft, a relatively large gear secured to the shaft between said walls, a pinion meshing with the gear, a stub shaft rotatably mounted with respect to the casing and to which the pinion is secured, a second pinion secured to the stub shaft, a ring gear meshing with the second pinion, an annular bearing on the outside of one of said walls on which the ring gear is rotatably mounted, and a driving chain sprocket secured to the ring gear, said annular bearing and ring gear lying between the sprocket wheel and the adjacent wall of the casing.

9. In a driving gear for a bicycle having a frame, a hollow casing fixed to the frame and having spaced vertical walls, a shaft extending horizontally across the casing and rotatably mounted with respect to each of the walls, means to rotate the shaft, a relatively large gear secured to the shaft between said walls of the casing, a stub shaft parallel to the first named shaft and rotatably mounted with respect to the casing, a pinion on said stub shaft meshing with the gear, a second pinion on said stub shaft, said stub shaft and pinions rotating as a unit, a ring gear meshing with the second pinion, an annular bearing on the outside of one of the walls of the casing for said ring gear, said annular bearing lying in a plane between the ends of the first named shaft and the latter having one end thereof passing through said annular bearing, and a driving chain sprocket wheel secured to the ring gear.

CONRAD J. ENGLERT.

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